Jq can't read some files

it probably isnt, no, but that would mean jq upstream would have to do something to show a more helpful error here …

in either case, jq does not qualify for classic, at least not for the reasons you mentioned in this thread … quoting from

Unsupported
    - access to arbitrary files on the system because the 
      application isn’t designed with confinement in mind...
    - access to arbitrary files on the system due to developer/user inertia